Technical Field
The present disclosure generally relates to electronic circuits and, more particularly, to a circuit for monitoring the power supply voltage of an integrated circuit.
Description of the Related Art
In many applications, the variation of the power supply voltage of an integrated circuit is desired to be monitored during its operation. Indeed, variations of this power supply voltage may induce problems in the circuit operation and/or reflect the circuit power consumption, and thus variations of the circuit activity and/or reflect behaviors of the circuit submitted to stress, for example, a disturbance which may be intentional (for example, an attack) or incidental (for example, an electrostatic discharge).
The power supply voltage is measured, for example, for test needs, by means of probes applied to different locations of the circuit and connected to a measurement device. The measurement is then particularly sensitive to electromagnetic disturbances generated by the use of conductive probes. Further, such a measurement is incompatible with a real time measurement during the operation of the circuit in its application environment.
Solutions internal to a circuit have already been provided to measure the variations of its power supply voltage. However, such solutions do not enable to measure non-periodic variations and the accuracy of the measurements depends on the actual value of the power supply voltage, the internal circuits being sensitive to disturbances of the power supply which is, most often, external to the circuit. Further, such measurements do not enable to measure voltages greater the voltage that can be withstood in the technology.